Location

San Diego, California

Session Start Date

5-24-2010

Session End Date

5-29-2010

Abstract

The introduction of AASHTO’s LRFD (load-and-resistance factor design) method for the design of MSE (mechanically stabilized earth) walls in 2004 has gradually replaced conventional state-of-the-practice seismic ASD (allowable stress design) method in some states, and by FHWA mandate should completely replace the ASD method by 2010. Limit equilibrium analyses based on Mononabe- Okabe (M-O) pseudo-static method had been the standard method of estimating the seismic external thrust and inertia force for MSE walls. Considering the flexible nature of MSE walls that allow deformation without compromising structural integrity, in the LRFD method, the displacement based pseudo-static method that was developed from Newmark sliding block analyses is used. In this paper, parametric studies are used to highlight the variations of soil reinforcement length/wall height ratios and internal lateral stresses between the LRFD and the current state-of-the-practice ASD methods. The results are compared with referenced past experimental studies and recorded seismic field performance of MSE walls. In addition, results from preliminary dynamic constitutive models are provided for comparison with displacements based on M-O pseudo static method. This paper shows that, by selecting an appropriate amount of tolerable wall deformation (i.e. between 25 and 200 mm as specified in AASHTO and FHWA), the seismic LRFD method for MSE walls is conservative and in general is in agreement with the conventional ASD method that has been widely used in the design of the MSE walls that have performed well during past major seismic events.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Meeting Name

Fifth Conference

Publisher

Missouri University of Science and Technology

Publication Date

5-24-2010

Document Version

Final Version

Rights

© 2010 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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May 24th, 12:00 AM May 29th, 12:00 AM

A Review of Seismic LRFD (Load-and-Resistance Factor Design) Method for MSE (Mechanically Stabilized Earth) Walls

San Diego, California

The introduction of AASHTO’s LRFD (load-and-resistance factor design) method for the design of MSE (mechanically stabilized earth) walls in 2004 has gradually replaced conventional state-of-the-practice seismic ASD (allowable stress design) method in some states, and by FHWA mandate should completely replace the ASD method by 2010. Limit equilibrium analyses based on Mononabe- Okabe (M-O) pseudo-static method had been the standard method of estimating the seismic external thrust and inertia force for MSE walls. Considering the flexible nature of MSE walls that allow deformation without compromising structural integrity, in the LRFD method, the displacement based pseudo-static method that was developed from Newmark sliding block analyses is used. In this paper, parametric studies are used to highlight the variations of soil reinforcement length/wall height ratios and internal lateral stresses between the LRFD and the current state-of-the-practice ASD methods. The results are compared with referenced past experimental studies and recorded seismic field performance of MSE walls. In addition, results from preliminary dynamic constitutive models are provided for comparison with displacements based on M-O pseudo static method. This paper shows that, by selecting an appropriate amount of tolerable wall deformation (i.e. between 25 and 200 mm as specified in AASHTO and FHWA), the seismic LRFD method for MSE walls is conservative and in general is in agreement with the conventional ASD method that has been widely used in the design of the MSE walls that have performed well during past major seismic events.